Fluoroscopic tables are commonly used for supporting a patient in a position to be irradiated by a beam of X-rays or other selected radiation. One conventional type of X-ray apparatus for diagnostic purposes includes a table having a top upon which the patient is positioned during the diagnostic procedure, and an X-ray source which is located above the patient and which directs X-rays downwardly through the patient and table top to a bucky which is carried by the table beneath the patient. The bucky includes an X-ray film cassette or carrier that positions the plane of the film substantially parallel to the table top. Such prior art apparatus is disclosed in U.S. Pat. Nos. 3,967,126 issued on June 29, 1976 to George W. Otto, Jr.
Early versions of the fluoroscopic tilt table, prior to development of appurtenances such as image intensifiers, automatic spot film devices, and spot film cameras, to name a few, involved relatively light weight components and such stages were easily counterbalanced. The resultant required efforts to manipulate these stagings were usually less than four pounds and were easily manipulated in all directions with manual effort of the fluoroscopist.
Later developments in the field of X-ray fluoroscopy included the production of X-ray image intensifiers which replace the bucky when it is desired to obtain immediate fluoroscopic viewing of an irradiated area. The image intensifier is an electron imaging device which converts an X-ray image first to an electron image and then to a visible image. Thus, when an X-ray beam is directed through a patient, there is formed an X-ray image which is directed onto the face of the image intensifier which immediately forms a visible image which may be viewed by the doctor or technician without waiting for development of films. Filming or television reproduction of the visible images produced by the image intensifier are also possible by known techniques.
One type of prior art system utilizing an X-ray image intensifier is disclosed in U.S. Pat. No. 3,912,936, issued Oct. 14, 1975 to Cunninghame et al.
Current designs of fluoroscopic tables must be capable of supporting X-ray source assemblies (generators and collimators) weighing as much as or more than about 150 pounds and receptor assemblies (image intensifiers, spot film cameras, optics) weighing as much as or more than about 250 pounds. Such current designs of fluoroscopic carriages or stagings are of massive and heavy construction in order to maintain proper alignment of components in all positions of the table. This results in the need for a large increase in manual effort to pan the assemblies over a patient due to increases in both inertia and friction.
Numerous power drives or assists have been designed to minimize the effort required by a fluoroscopist to perform the adjustment of the apparatus. Current designs include a "C" shaped carriage the upper arm of which supports the receptor assembly, with the lower arm supporting the X-ray source assembly. The carriage is adjustable longitudinally of the table to move the receptor and source assemblies as a unit, and each assembly is individually movable on its respective carriage arm in a direction transversely of the table. However, such structures possess the problems mentioned hereinabove, in addition to being costly to manufacture and expensive to maintain in terms of bearing wear, etc.